Quick change plating bath fixture



p 1966 J. c. GADE 3,275,544

QUICK CHANGE PLATING BATH FIXTURE Filed April 15, 1962 2 Sheets-Sheet l INVENTOR. John G. Gode A TORNEYS Sept. 27, 1966 J. c. GADE QUICK CHANGE PLATING BATH FIXTURE 2 Sheets-Sheet 2 Filed April 13, 1962 INVENTOR.

John C. Gode ATTORNEYS United States Patent Office 3,275,544 QUICK CHANGE PLATING BATH FIXTURE John C. Gade, Warren, Ohio, assignor to Rockwell-Standard Corporation, a corporation of Delaware Filed Apr. 13, 1962, Ser. No. 187,291 2 Claims. (Cl. 204297) The present invention relates to apparatus for electroplating relatively large metal articles and more in particular to an article support or rack therefor.

In electroplating or polishing large metal articles, such as automobile bumpers, it is necessary to firmly attach the articles for immersion in the liquid electrolyte on suspended racks which are connected to the electric circuit to render the articles cathodic and anodic respectively. Due to the weight and large dimensions of such articles the supporting racks must be heavy and must provide adequately strong means for secure attachment such as heavy pins, bolts and nuts.

In electroplating automobile bumpers which are of non-uniform shape, size and weight it is common practice to suspend them on the support racks in either horizontal or vertical position depending on their configuration. Production requirements often make it necessary to change from one type of bumper to be plated to another, this requiring also a change in the plating bath fixtures, such as from horizontal support racks to vertical. Due to the conventional heavy equipment involved, these changeovers have resulted in considerable waste of time and excess work which is expensive. Actually production schedules had to be revised since for example it was economically prohibitive to have both vertical and horizontal plating in the plating line set-up.

In one type of presently used plating equipment for heavy, irregular articles, yoke type cross bars are provided which are supported at their centers on an electric current carrying bus bar rail. Usually two cross bars comprise a unit, and detachable racks are vertically suspended from the cross bar ends in properly spaced apart relation.

Two diiferent types of racks are used to support articles to be plated in either vertical or horizontal position for immersion in the plating bath. Prior to the invention, these article support racks were removably attached to the cross bar ends by heavy clamps secured by bolts and pins which had to be laboriously loosened or removed in order to slide the clamps off the cross bar ends. Since there are four support racks for each unit and several units may form a plating line set-up, a changeover from one type of rack to another has previously required the time of three or four men for four to six hours. In large scale plating operations, changeovers from one work set-up to anotherare apt to occur more frequently and the required down-time is far too excessive and expensive for economical operation.

The present invention provides a quick, rack changing fixture arrangement for such units which cuts the down-time approximately in half. It provides a rack mounting which comprises a slotted clamp onto which the rack may be hung securely or detached therefrom without the necessity of loosening or removing bolts or pins or the clamp itself.

A major object of the invention is to provide a novel electroplating bath fixture of the type wherein article support racks are mounted on cross bars which in turn are supported on a bus bar, the racks having speedily detachable suspension mounts on the cross bars eliminating the use of fasteners.

It is another object of the present invention to provide a novel plating bath fixture comprising a clamp fixed on a cross bar in a plating line and having a shaped slot and a mating member directly attached to the article 3,275,544 Patented Sept. 27, 1966 support rack which has a head shaped to fit into the clamp slot for quickly attaching and detaching the support rack. Further to this object the mating member and slot have downwardly converging support faces.

Another object of the invention is the provision of means by which support racks in plating bath equipment can be quickly exchanged without loosening fasteners so as to reduce down-time and expenses during a changeover period.

Other objects and features will become apparent from the following description and the appended claims in connection with the appended drawings in which:

FIGURE 1 is a vertical section through a plating tank schematically showing articles to be plated supported according to a preferred embodiment of the present invention;

FIGURE 2 is an enlarged section through one cross bar showing the quick change fixture in detail substantially along line 2-2 of FIGURE 1;

FIGURE 3 is an end view of the rack mount of FIG- URE 2, with the lower rod section removed;

FIGURE 4 is a top view of the rack mount of FIG- URE 2;

FIGURE 5 is a view taken along line 5-5 of FIG- URE 3 and showing the method of assembly of the fixture; and

FIGURE 6 is a cross section through the rod of the fixture along line 6-6 of FIGURE 5.

With reference to FIGURE 1, which illustration is only schematic insofar as the general plating equipment and shape of the article to be plated is concerned, a plating tank 10 has a liquid electrolyte level indicated at 12. The parallel bus bars 14 and 16 extend longitudinally along the top of the tank and are connected to an adequate number of electrodes, two of which are shown at 18 and 20, extending into the: liquid adjacent the walls the tank. Centrally above the tank extends longitudinally a support beam 22 which in this embodiment is an electric current carrying bus bar.

A yoke type cross bar 24 having arms 26 and 28 extending horizontally away from bus bar 22 extends laterally across the tank 10 above the level of bus bars '14 and 16. Cross bar 24 is supported on bus bar 22 at 25 for sliding movement longitudinally of the tank and is usually made of good electrical conducting material to transfer current from bus bar 2 2 to a .pair of identicalsupport racks 30 extending vertically downwardly from the outer ends of the arms 26 and 28 into the tank 10 to be partly immersed in the electrolyte. Racks 30 are likewise made of good electrical conducting material, such as copper, and may be covered with suitable electrical insulating material except where they are connected to cross bar 24. Racks 30 may be of any suitable configuration to support a number of rather large and heavy articles 32 thereon, which in the present instance comprises automobile bumpers, and other diflicult to handle articles such as automobile grilles, large stampings, and large irregular metal shapes can be substituted.

In the present instance, the large articles 32 are suitably supported on the racks 30 with the long dimension in vertical position. Electrical contact 341 is provided between each rack 30 and associated article 32, and a connecting support element 35 extending between each rack 30 and the associated article 32 cooperates with a tie bar 36 at the lower ends of the racks 30 to draw the articles 32 tightly against electrical contacts 34 to assure a good and secure electrical connection. Thus each article 32 has the polarity of bar 2-2.

The foregoing description and illustration of the manner of connecting articles 32 to the racks 30 is intended to be general only since a variety of suitable and known structures may be employed without departing from the spirit of the present invention.

In plating or electropolishing large and awkward articles such as those with which the present invention is mainly concerned various articles must be supported on racks in either vertical or horizontal positions as explained, and for this reason two types of racks are provided which according to production requirements are interchanged sometimes rather frequently in one plating set-up. This operation of interchange is accomplished without the use of fasteners in the invention.

The racks 30 are permanently fixed, as by welding or riveting at 39, to the bifurcated lower end 38 of rod 40 which has a head 42 in the shape of an inverted truncated square cross section pyramid as shown in FIG- URES 2-6. The base of the pyramid is at the top and the head '42 tapers to approximately the diameter of cylindrical section 44 of rod 40. As shown in FIGURES 4 and 6, an open ended slot 46 is formed in the flange 48 of bracket 50 which has a main body 52 formed with two rectangular apertures 54 and 56 intersecting each other at right angles to selectively attach the bracket 50 to the cross bar in 90 related positions. Here the cross bar 24 passes slidably through aperture 54 and set screw '58 is threaded into the bracket to engage bar 24 to hold bracket 50 in a fixed location laterally in the tank and improve the electrical contact. Slot 46 in the bracket flange 48 intersects a square section socket 60 having sloping downwardly converging sides 62, and the slope of sides 62 corresponds to the angularity of the sides 43 of pyramid head 42 of rod 40. When rod 40 is slidably inserted through the open end of slot 46, as illustrated in FIGURE -5, and then allowed to settle downwardly, the sides 43 of head 42 are wedgingly seated upon the corre- .sponding side-s 62 of socket 60 to provide a rigid and sha'keproof suspension connection. Thus bracket 50 is attached to cross bar 24 by a tight sliding fit through aperture 54 and rigidly secured to the cross bar by lock screw 58 to assure good electrical contact between the cross bar and bracket. The rack rod 40 is in turn wedged into tight contact with bracket 50 by the enlarged head suspension aided by the suspended weight and will not loosen during insertion of the rack and the article supported thereon into the electrolyte even though a certain degree of buoyancy is imparted to the article and rack during immersion. The rod 40 thus has a non-rotatable coupling with bracket 50. Thus excellent electrical con-tact is assured at all times and the articles are securely supported.

When it is necessary to change from one plating setup to another requiring different supporting racks, it is merely necessary to remove rack 30 together with its attached rod 40 as a unit out of the bracket 50 and insert a different type rack 30 already attached to an identical pyramidal head attaching rod. This involves only lifting the rack and rod unit to the position of FIGURE and sliding it laterally in slot 46 until free of bracket 50, and then pulling the unti out of the electrolyte. The rod 40 for the new rack can be attached at leisure before the changeover is necessary.

It will be appreciated that any number of cross bars 24 may be provided for a plating tank 10, with each end of each cross bar detachab'ly mounted, as by slide guide 54 and lock screw 58, on a bracket 50 which in turn has an open sided socket 60 for detachably suspending a headed rod 40 carrying a rack 30. The detachable socketrod head connection, which is the only separable connection during changeover, is free of threaded or like fasteners that might rust or corrode, and the wedge type socket suspension arrangement required no particular accuracy of interfit between the sides of head 42 and socket 60.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

-1. In an electrolytic apparatus of the type characterized by a plating tank having at least two laterally spaced parallel electrical conductor bars extending along the top of the tank with electrodes depending from said conductor bars into the electrolyte in said tank and an intermediate current carrying bar, a laterally extending current carrying cross bar slidably connected to said intermediate current carrying bar and extending toward said conductor bars, brackets slidably mounted on the opposite ends of said cross bar for displacement in the direction of the electrodes, each said bracket having a downwardly tapered non-circular open through socket provided with a restricted side opening, a hanger unit readily removably mounted on said bracket comprising a shank of such lateral dimensions as to fit laterally through said socket side opening, an enlarged tapered non-circular head of the same shape as the socket seated within said socket with a non-rotatable wedge fit and means below said shank rigidly mounting a work holding rack suspended in the electrolyte in suitable spaced relation to an electrode.

2. The apparatus defined in claim 1, wherein said socket and said head are pyramidal in shape.

References Cited by the Examiner UNITED STATES PATENTS 825,591 7/ 1906 Engelhard 204--297 1,715,357 6/1929 Hall 204-297 1,908,830 5/1933 Edison 204--297 2,760,929 8/1956 Shepard et al. 204297 JOHN H. MACK, Primary Examiner.

D. R. JORDAN, Examiner. 

1. IN AN ELECTROLYTIC APPARATUS OF THE TYPE CHARACTERIZED BY A PLATING TANK HAVING AT LEAST TWO LATERALLY SPACED PARALLEL ELECTRICAL CONDUCTOR BARS EXTENDING ALONG THE TOP OF THE TANK WITH ELECTRODES DEPENDING FROM SAID CONDUCTOR BARS INTO THE ELECTROLYTE IN SAID TANK AND AN INTERMEDIATE CURRENT CARRYING BAR, A LATERALLY EXTENDING CURRENT CARRYING CROSS BAR SLIDABLY CONNECTED TO SAID INTERMEDIATE CURRENT CARRYING BAR AND EXTENDING TOWARD SAID CONDUCTOR BARS, BRACKETS SLIDABLY MOUNTED ON THE OPPOSITE ENDS OF SAID CROSS BAR FOR DISPLACEMENT IN THE DIRECTION OF THE ELECTRODES, EACH SAID BRACKET HAVING A DOWNWARDLY TAPERED NON-CIRCULAR OPEN THROUGH SOCKET PROVIDED WITH A RESTRICTED SIDE OPENING, A HANGER UNIT READILY REMOVABLY MOUNTED ON SAID BRACKET COMPRISING A SHANK OF SUCH LATERAL DIMENSIONS AS TO FIT LATERALLY THROUGH SAID SOCKET SIDE OPENING, AN ENLARGED TAPERED NON-CIRCULAR HEAD OF THE SAME SHAPE AS THE SOCKET SEATED WITHIN SAID SOCKET WITH A NON-ROTATABLE WEDGE FIT AND MEANS BELOW SAID SHANK RIGIDLY MOUNTING A WORK HOLDING RACK SUSPENDED IN THE ELECTROLYTE IN SUITABLE SPACED RELATION TO AN ELECTRODE. 